Are there insoluble Sudoku puzzles?
Are there some with more than one solution?
I think both statements may be true.
Gerrygeek wrote:I believe I can solve ANY sudoku puzzle. Please post a one you believe to be insolvable and I will try to solve it.
coloin wrote:Gerrygeek wrote:I believe I can solve ANY sudoku puzzle. Please post a one you believe to be insolvable and I will try to solve it.
How do you do it then ?
C
I believe I can solve ANY sudoku puzzle. Please post a one you believe to be insolvable and I will try to solve it.
gerrygeek wrote:But what of my questions please.
CAN there be more than one solution to a Sudoku problem which obeys the normal rules?
Can some which seem OK have NO solution?
Can all soluble problems be solved by a computer program? Has anyone written such a program?
m_b_metcalf wrote:gerrygeek wrote:Can all soluble problems be solved by a computer program? Has anyone written such a program?
Yes and yes, if you mean by brute force. However, Sudoku Explainer can solve all known puzzles by logic (afaik); it might take several hours for a really hard one.
sudopedia wrote:A Forcing Chain is actually a move simulator. Instead of placing a digit in a cell, we use the chain to find out what would happen when we make that move. "Forcing" refers to the fact that placing a digit in one cell can force another cell to another digit.